safe-navigator

A safe navigation operator for javascript that allows you to access nested objects without throwing an error if you try to access the key of an undefined value.

Install with npm i safe-navigator

How does it work ?

If you want to access obj.key1.key2.key3, you can import the package as safe and try safe(obj, "key1.key2.key3") and even if key1 does not contain a key called key2 and you try to access key3 in an undefined value of key2, the function will return the value of undefined without throwing an error. If you pass a third argument to safe(obj, "key1.key2.key3", []), incase the value is undefined, the fallback will be returned by safe.

If you don't pass a second parameter to the function, the object passed as first parameter will be returned.

If you dont return any parameters, the function will return undefined.

#Updates v1.1.0 : Added support for accessing array in a nested javascript object. v1.1.2 : Added a fallback as third argument to safe function

Example:

const farm = { farmer: { name: 'Steve' } };
console.log(farm.farmer.name); //will return 'Steve'
console.log(farm.farmer.name.age.old); //will throw an error

Now lets try it with safe

const safe = require('safe-navigator');
const farm = { farmer: { name: 'Steve' } };
console.log(safe(farm, 'farmer.name.age.old')); // undefined.
console.log(safe(farm, 'farmer.name')); // will return 'Steve'

Update v1.1.1: Fallback
console.log(safe(farm, 'farmer.name.age.old', "fallback")); // will return 'fallback'.

Update v1.1.0: Arrays inside nested Objects

const farm = { 
    farmer: { 
        name: 'Steve', 
        farmAnimals: ['Horse', 'Cow'], 
        animalDetails: [ {horse: { name: 'john'} }, { cow: { name: 'sam' } }],
        pairs: [['john','michelle'], ['sam','edna']]
        } 
    };

    console.log(safe(farm, 'farmer.farmAnimals[0]')); // will return 'Horse'
    console.log(safe(farm, 'farmer.animalDetails[0].horse.name')); // will return 'john';
    
    Note: 2D or multi-dmensional arrays are not natively supported in the string passed to safe.

    To work with multi-dimensional arrays, use [] after the safe fn returns the parent array.
    console.log(safe(farm, 'farmer.pairs[0]')[1]); // returns 'michelle'